Manufacture of refined oils



washed with water.

ERNEST B. COBB, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO STANDARD DEVELOP- MENT COMPANY, A. CORPORATION OF DELAWARE.

mmuracruan or REFINED one.

No Drawing. Application filed April 8,

The present invention relates to the manufacture of refined oils and more particularly of refined viscous oils such as lubricating oils, water white or medicinal oils and the like.

In the refining of such oils, the stock, which is in general a distillate or cut obtained from crude oil after the kerosene or burning oil out has been removed, is subjected to an acid treatment with strong sulfuric acid, for example, with 66 B. acid or fuming acid. The treatment with sulfuric acid may be heavy or light; that is, with greater or less amounts of acid, in accordance with the extent to which the refining of theoil is to be carried. The action of the acid upon the hydrocarbons of the oil appears to form, among other com ounds, sulfo-compounds which are in part dissolved in the sludge which is settled out of the oil, and are in part retained in the oil. The sulfo-compounds retained in the oil both in their acid state and when neutralized, appear to act as emulsifying agents, causing the oil to readily form'persistent emulsions when In the case of water whiteand' medicinal oils they likewise tend to discolor the oil and to make it unsuitable for internal administration. The removal of these sulfo-compounds or emulsion inducing constituents substantially removes the tendency of the treated oil to emulsify. I

The vproportion and the specific characteristics'of the sulfo-compounds retained in the-oil vary to some extent with the characterof oil treated and with the natureof the treatment. Thus. in a light acid treatment with 66 B. acid for the production of lubricating oils, a less proportion of these compounds appears to be formed than in the heavy acid treatments with fuming acidem ployed in the case of the manufacture of White oils or medicinal oils. The character of the oil appears to influence to a marked degree the ease of removal of the retained sulfo-com ounds. Thus it has been found that-Russian oil distillates are more amenable-to the purifying treatment hereinafter setg iorth than distillates from coastal oils and-from parafiin bearing oils such as Pennsylvania or Mid-Continent oils. Thus, although Russian oils subjected to a heav fuming acid treatmentmay be directly purified by the present process, the other oils,

earth.

1922. Serial No. 550,865.

particularly those of 150 seconds viscosity or higher, can best be purified by such treatment after a lighter acid treatmentorfafter a retreatment following a previous acid treatment and removal of sulfa-compounds.

In accordance with the present invention, the oil to be refined is subjected to the desired acid treatment which may be with 66 Baum acid or fuming acid and in one or a plurality of dumps. The sludge is removed from'the treated oil as completely as p0ssible by settling, and, if equipmentpermits, it is desirable that this settling be continued for two or three days or even longer. The separated oil is then heated to a; temperature between 350 and 500 F., and preferably at about380 F. for a period'of fifteen hours or longer. -Twent hours has been found most suitable. During thisheating it is found that the sulfo-compounds tend to break down, with'the formation of some volatile and some non-volatile products, In order to carry off the volatile produets formed, itj'is found desirable to pass steam through the oil during the heat treatment, the steam being also effective in agitating the oil to cause uniform heating thereof and in removing any volatile oil present not desired in the final product. During the heat treatment acidity of the oil decreases, and it becomes substantially neutral at the end of the treatment. The removal of the nonvolatile products' of decomposition of the sulfo-compo'unds from the oil, it they are not excessively large in amount, ma be efi'ected by filtration o the oil through i iillers earth or Florida clay. When the proportion of decomposition products formed is so large or theyare of'such character-that filtration through Florida clay alone is not wholly effective or is uneconomical, the colloidal products of decomposition maybe in whole or in part removed by'washing with acid, preferably sulfuric acid of66. B. or weaker. After this'washing, the oil having been thoroughl settled, its refining may be complete by direct filtration through fullers The following examples, practice of the present inventi i i Example No.1.

A Russian oil distillate of 300 to 325 sec onds' viscosity (Saybolt) at F. was treated for the production of a medicinal oil illustrate the 7 500 F., and preferably about be immediately cooled and filtered after this v unvolatilized products of with fuming sulfuric acid, using 30% by volume of fumin acid containin 20% anhydride. The acid was used in ve nearly equal dumps, the oil I being Ipreferably brought to a temperature of 7 or lower position of the sulfo-compounds, togetherwith any constituents of the oil which undesirably reduce its-flash point. The oil may roportion of ecomposition colloid heat treatment; however, the

present in it, in part appearing as -particles, renders filtration at this pointuneconomical.

It is preferred to treat the oil with an acid, for example,-66 B. sulfuric acid or lighter acid, .5 to 10% by volume be ing a suitable proportion. I On settling, itis found that the oil has been to a consi able extent freed from; the suspended colloids,

containing 20% anhydride,

which apparently go into the acid la er. After thorough settling, say from two ays to a week, the oil isfiltered through fullers earth or Florida clay. The resulting oil has Saybolt at a viscosity of 200 to250 seconds 100 F. and a flash point oi 350 to 375 F.

Example No. 2. In preparing contain both naphthenic and asphaltic compounds, a suitable distillate is selected, for example one having a viscosity of 450 seconds Saybolt" at 100 F., a gravity of about 22 B. and a flash point of 370 F. This stock is treated with fuming sulfuric acid a suitable proportion being 37% by volume. The treatment is preferably eflected in five dumps 0 approximately equal proportions. After each dump the oil is settled, suitably from twentyfour to forty-eight hours and the sludge removed. Before each dump the oil is preferably cooled to below F. After the last treatment, the sludge is drawn OE and the batch is neutralized, for exam le, with 12 B. caustic. soda solution. 'l he alkali sludge is removed and the oil may then, if desired, be blown with air at about 180 to 200 F. This air blowingremoves water. tilled'with fire and'steam to.a bottom of 5 to 10%, the distillate fraction (-95%) bein collected as a whole with the exception o-fthe light constituents which might undea medicinal oil from West Colombia or Coastal stock, which appears to f fuming acid being ment in the manner described for the remov- After neutralization the oil is dissirably reduce the two dumps of approximately equal propor- I tions. After this acid treatment the oil is allowed to settle for as long a period as possible,

two or three. days at least. The sour oil is then subgected to the heat treatment above describe being heated preferably to 380 to 410 F. for about twenty hours, with .the injection of steamto effect the removal of volatile decomposition products and sulphur dioxide. At the end of the heat treatment the oil is cooled and filtered through fullers earth, the preliminary coagulation of suspended matter with acid as described in the first example usually necessary in this case. The finished oil has a viscosity 05200 to 210 seconds Saybolt at 100 and a gravity of about 29 Ewample N 0 3.

-A distillate from'a Coastal crude having a gravity of 22.3 B., a flash point of 325 F., a viscosity of 125 seconds .Saybolt at 100 F. and a zero cold test is, treated for the production of a white medicinal oil in being desirable but not the manner described in Example No. 2,

above, except that the pressingof the distillate from the oil after the first acid treatment is unnecessary and the heat treatment or steaming of the oil after the second acid treatment is carried out at about 380 F.

The finished oil is water White, and has a gravity of 29.8 B., a flash oint of 325 F., a viscosity of secon s -Saybolt at 100 F. and a 10 F. cold test. A distillate of this character may likewise be treated in the same manner as the Russian .oil distillate in Example 1,

followed by a heat treatal of sulfo-compo'unds, and this, in turn, by a light acid treatment and filtration.

Although the present inventionhas described in connection with the details of specific methods for carrying it-into efiect, it is not intended that these shall be rearded as limitations upon thescope of the invention, except in so far as retained in the accompanying claims.

' I claim:

1. The process of destroying. emulsion inducin compounds including sulfo-com- Booms present in sulfuric acid treated oils y reason of the acid treatment thereof which comprises maintaining such oils at a a vigoroustreatment with v been I pounds including sulfo-compounds is effected within the oil body and removing products of decomposition from the oil.

3. The process of destroying emulsion inducing compounds including sulfo-compounds. present in sulfuric acid treated oils by reason of theacid treatment thereof which comprises maintaining such oils at a temperature of 350 to 500 F. until decomposition of' such emulsion inducing compounds including sulfo-compounds is effected within the oil body, and subsequently filtering the oil.

4. The process of destroying emulsion inducin compounds including sulfo-compoun s present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at a temperature of 350 to 500 F. until decomposition of such emulsion inducing compounds including sulfo-compounds is effected within the oil body and passing steam through the oil during the heat treatment thereof.

5."The process of destroying emulsion inducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at a temperature of 350 to 500 F. until decomposition of such emulsion inducing compounds including sulfo-compounds is effected Within the oil body, passing steam through the oil during the heat treatment,

and subsequently filtering the oil.

, 6. The process of destroying emulsion inducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at a temperature of 350 to 500 F. until decomposition of such emulsion inducing compounds including sulfo-compounds is effected within the oil-body, and washing the oil with an acid solution. 7. The process of destroying emulsion inducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at a temperature of 350 to 500- F. until decomposition of such emulsioninducing compounds including sulfo-compounds is effected within the oil body, washing the oil with an acid solution, separating and filtering the oil.

8. The process of destroying emulsion inducing compounds including sulfo-comounds present in sulfuric acidtreated oils y reason of the acid treatment thereof which comprises maintaining such oils at, a. temperature of 350 to 500 F; until decompo-- sition of such emulsion inducing compounds includin sulfo-compounds is, effected with; in the 011 bod passing steam through thcoil during such treatment andwashing the treated oil with an acid solution. 7

9. The process of destroying emulsion inducing compounds including, sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at-a temperature of 350 to 500 F. until decomposition of such emulsion mducmg compounds including sulfo-compounds is ef-' fected within the oil body, passing steam' through the oil durin the heat treatment,

- washing the treated 011. with an acid solution, separating and filtering the oil.

10. The process of destroying emulsion inducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at 380 to 410 F. for eighteen totwenty hours.

11. The processof destroying emulsion inducing compounds pounds present in sulfuric acid treated oils by reason of the acid treatment thereof including. sulfo-comwhich comprises maintaining such oils at-380 to 410 F. for eighteen to twenty. hours and removing products of decomposition from the oil.

12. The process of destroying emulsion inducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at 380 to 410 F. for eighteen to twenty hours and subsequently filtering the oil.

.13. The process of destroying emulsion inducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at 380 to 410 F. for eighteen to twenty hours and passing steam through the 'oil during the heat treatment thereof;

14. The process of destroying emulsion inducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at 380- to 410 F. for eighteen to twentyhours, passing steam through the oil during the heat treatinentpand subsequently filtering the oil.

15. The process of destroying emulsion in ducing compounds including sulfo-com= pounds present in sulfuric acid treated oils by reasonof the acid treatment thereofrating and filtering the oil.

17. The process of destroying emulsion in- I ducing compounds including sulfo-compounds present in sulfuric acid treated oils by reason of the acid treatment thereof which comprises maintaining such oils at 380 to 410 F. for eighteen to twenty hours, passing steam through the oil durin such treatment and washing the treated 011 with an acid soluti'gn.

- 18. The process of destroying emulsion inducing compounds including sulfo-come pounds present in sulfuric acid treated oils bv reason of the acid treatment thereof which comprises maintaining such oils at 380 to 410 F. for eighteen, to twenty hours, passing steam through the oil during the heat ,treatment, washing the treated oil with an aclid solution, separating and filtering the o1 1 19. The process of refining VlSCQllS hydrocarbon distillate which comprises acting thereupon with strong sulfuric acid, separating the sour oil, heating it to about 380 F. for eighteen to twenty hours while passing steam therethrough and subsequently filtering the oil.

20. The process of destroying emulsion inducing compounds including sul'fo-compounds present in a heavy oil distillate containing the heavy constituents of a 90 to 95% distillate fraction of an oil previously subjected to heavy treatment with sulfuric acid,

said distillate having been subsequently subjected to a. like treatment with fuming sulfuric acid and being sour'in character, com prising heating such sour distillate oil to about 380 F. for 18 to 20 hours while passing steam therethrouglfl and filtering the oil.

ERNEST B. COBB. 

